From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man3/sechash.html | 195 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 man/man3/sechash.html (limited to 'man/man3/sechash.html') diff --git a/man/man3/sechash.html b/man/man3/sechash.html new file mode 100644 index 00000000..2e055465 --- /dev/null +++ b/man/man3/sechash.html @@ -0,0 +1,195 @@ + +sechash(3) - Plan 9 from User Space + + + + +
+
+
SECHASH(3)SECHASH(3) +
+
+

NAME
+ +
+ + md4, md5, sha1, hmac_md5, hmac_sha1, md5pickle, md5unpickle, sha1pickle, + sha1unpickle – cryptographically secure hashes
+ +
+

SYNOPSIS
+ +
+ + #include <u.h>
+ #include <libc.h>
+ #include <mp.h>
+ #include <libsec.h> +
+ + DigestState*     md4(uchar *data, ulong dlen, uchar *digest,                    DigestState + *state) +
+ + DigestState*     md5(uchar *data, ulong dlen, uchar *digest,                    DigestState + *state) +
+ + char*           md5pickle(MD5state *state) +
+ + MD5state*        md5unpickle(char *p); +
+ + DigestState*     sha1(uchar *data, ulong dlen, uchar *digest,                    DigestState + *state) +
+ + char*           sha1pickle(MD5state *state) +
+ + MD5state*        sha1unpickle(char *p); +
+ + DigestState*     hmac_md5(uchar *data, ulong dlen,
+ +
+ + +
+ + uchar *key, ulong klen,
+ uchar *digest, DigestState *state) +
+ +
+ +
+ +
+ + +
+ + + +
+ +
+ DigestState*     hmac_sha1(uchar *data, ulong dlen,
+ +
+ + +
+ + uchar *key, ulong klen,
+ uchar *digest, DigestState *state)
+ +
+ +
+ +
+

DESCRIPTION
+ +
+ + +
+ + These functions implement the cryptographic hash functions MD4, + MD5, and SHA1. The output of the hash is called a digest. A hash + is secure if, given the hashed data and the digest, it is difficult + to predict the change to the digest resulting from some change + to the data without rehashing the whole data. Therefore, if + a secret is part of the hashed data, the digest can be used as + an integrity check of the data by anyone possessing the secret. + +
+ + The routines md4, md5, sha1, hmac_md5, and hmac_sha1 differ only + in the length of the resulting digest and in the security of the + hash. Usage for each is the same. The first call to the routine + should have nil as the state parameter. This call returns a state + which can be used to chain subsequent calls. The last call + should have digest non-nil. Digest must point to a buffer of at + least the size of the digest produced. This last call will free + the state and copy the result into digest. For example, to hash + a single buffer using md5:
+ +
+ + uchar digest[MD5dlen];
+ md5(data, len, digest, nil);
+ +
+ + +
+ To chain a number of buffers together, bounded on each end by + some secret:
+ +
+ + char buf[256];
+ uchar digest[MD5dlen];
+ DigestState *s;
+ s = md5("my password", 11, nil, nil);
+ while((n = read(fd, buf, 256)) > 0)
+ +
+ + md5(buf, n, nil, s);
+ +
+ md5("drowssap ym", 11, digest, s);
+ +
+ + +
+ The constants MD4dlen, MD5dlen, and SHA1dlen define the lengths + of the digests. +
+ + Hmac_md5 and hmac_sha1 are used slightly differently. These hash + algorithms are keyed and require a key to be specified on every + call. The digest lengths for these hashes are MD5dlen and SHA1dlen + respectively. +
+ + The functions md5pickle and sha1pickle marshal the state of a + digest for transmission. Md5unpickle and sha1unpickle unmarshal + a pickled digest. All four routines return a pointer to a newly + malloc(3)’d object.
+ +
+

SOURCE
+ +
+ + /usr/local/plan9/src/libsec
+ +
+

SEE ALSO
+ +
+ + aes(3), blowfish(3), des(3), elgamal(3), rc4(3), rsa(3)
+ +
+ +

 +
+
+ + +
+
+
+Space Glenda +
+
+ + -- cgit v1.2.3